Hand and indicator for watches and like articles



, H. 'F. cumz. v V HAND AND INDICATOR FOR WAI'CHESAND LIKE ARTICLES.

APPLICATION FILEDVOCT- I2 I92]- Patented May 9, 1922.

Q I. a a

INVENTOR.

UNITED STATES PATENT oer-res.

HERMANN r. CUNTZ, or HARTFORD, ooN Eo'rIcUT, AssIsNo-R To' mERIoANRADIUM COMPANY, OF NEW YORK, N. Y., A co oR TIoN or NnwYoRK.

HAND AND INDICATOR noR WATCHES AND LIKE ARTICLES.

' Specification of Letters Iatent.

Original application filed July 2, 1921, Serial No. 482,095. Divided andthis application filed October 12,

'ofNew York, have invented certain new and useful Improvements in Handsand Indicators for Watches and like Articles, of which the following isa specification, ref-. erence being had to the accompanying drawings,illustrative of, particular embodiments of my invention, this being adivision of my application Serial No;.482,095, filed July 2,

.1921, allowed October 3, 1921.

This invention relates toindicators such as the hands of clocks,watches, gauges, meters and other devices, and instruments, and forlikeor similar devices, as may appear from the following specification.Particularly in such indicators the invention -re lates to. providingthem in a form or construction permitting advantageous equipment withluminous material, so that the indicators or hands may be readilyvisible v and readable at night and at the same time aifording accurateand easy-reading or readily discerning of an indicator or indicators andtheir position with respect to graduations by outside light such as bydaylightor when visible by ordinary illumination.

The application of luminous material involving compounds of radio-activeand radio-responsive material, has heretofore been practised byembodying such permanently luminous compounds in a-recess in the handsof instruments and particularly in watch and clock hands sothat asufficient bulk of the material is held spread over a sufiicient area toprovide an amount of luminosity to an extent and for a sufficientdistance suitable for the particular instruments or case involved; or insome cases the permanently self-luminous compound is spread over thesurface of a hand with suitable protective covering to keep it in place.A reasonable area is requiredwith a considerable width with respect tothe length in a line, intended to be luminous in the dark, sufiicientto.

provide visible luminosity at a, distance of a foot or several feet oryards,depending .1921, Serial No. 507,240.

upon the particular useto which the perma- Patented May 9, 1922.

nently illuminated article is adapted. In

'view of the relatively larger width of line required for this darktimeluminous .efiec't,

the indicator, hand ,or pointer are of a greater width than permitsaccurate reading, in the daytime or under conditions of ordinary outsideillumination, fore, becomes a problem to provide such de It, thereviceswith permanent-1y luminous material in a manner whereby accurate readingof the time or accurate reading of instruments, as to the registrationof point ers 'WIth graduations, cantbe assured or in any event canbecome a matter of greater'accuracythan I has here ofo're been the caseby day and night. r

In the'case of pointers or indicators and hands for watches, abroadsurface coveredwith radio-luminous material, backed up by a relatively.dark background involves all the inaccuracy incident tlo'a broad linecompared with a very fine hair line. or narrow marker which should beused in ordinary or 1 full illumination for accurate determination ofcalibration registration.v I, therefore, provide a pointer or hand withsurface of a relatively s'uliicient width to carry .an arm ple area ofradio-luminousmaterial for the desired degree ofvisibilitv in thedarkness, but I, provide medially or in the axis of such a pointer 'orhand, a narrow contrasting lineof non-luminous material and ofcontrasting color with the luminous material in thedaytime or whensubject to outside illumination. Suchcentral line of nonluminousmaterial provides for accurate reading in the daytime and the provisionof such .a line whether .on-the pointer, calibration', markingornumerals, supplements the art heretofore known by giving .to the use ofradio-luminous compound on instruments and other devices an assurance ofaccuracy for ordinary readlng by outside light whic has notheretoforebeen the case.

The provision of such distinct no'n-luminous accurate marks, whether inan-indicator or In a graduation, or otherwise, in-

volves modifications from structures heretofore used, which maybeprovided .in nu-' merous ways but require structural changes in suchparts not heretofore known and of which articular embodiments I haveherei more detail with reference to the accom the edge ofthe strip asdesired.

' The central rib permitsthe embedding of the radio-luminous material Din a manner. that affords sufiicient contact of the material panyingdrawings,'in which:

Fig. 1 is a plan view of a pointer or hand with the daytime reading linein arrowhead at the tip and centrallythroughout the main body of thepointer: 1

Fi 2 is a cross-section of a pointer on the line 2-2 of Fig. 1. v

Fig. 2 is a similar cross-section of a pointer showing a modified formof attachment for the medial daytime reading line.

Fig. 2 is a cross-section of a pointer with a modified form ofarrangement and con-. nection between the baseand'the daytime readingline.

Fig. 3 is a plan view of the pointer in Fig. 2, showing. the contrastingdaytime reading lines compared with the radio luminous field.

Fig. 4 is a side elevation of Fig. l.

The pointer or hand A comprises a strip of very thin material'and whichis-usually metal and preferably steel, which is formed with the usualhub a and terminates at theopposite end with its side converging to apoint a. As shown, the middle of thestrip is crimped to form a ridge IB,and the converging edges near the tipare turned up to form lateralconverging ridges C. These ridges B and (I, and particularly the former,give a horizontal stiffness so that the strip of which the hand orpointer is made may be of thinner material than usual,-With the ridge Bforming astrengthening medial flange or web. However, the height of thiscentral rib is such as to provide between it and the border or sides ofthe strip a recess which provides for the embedding of a layer ofradioluminous material on either side of the central rib and extendingto the edge or as near and a vehicle or coating which holds theradio-luminous, material to the pointer, but also permits uniformandready application on either side of the middle ridge,

whereby the ridge is left clear and clean of lumlnous material and beingof a contrasting.

color, such as blued or otherwise treated steel,

it constitutes auniform dark medial line as viewed in the daytimecompared with the lateral areas of light colored radio-luminouscompounds. The radio-luminous compound area can extend directly to thepoint within the converging ridges CC whereby a pointed luminous areaaffords the desired visibility in the dark, while the ridges C-C protectthe tip and keep. the radio-luminous material more permanently-inposition-for a long period of years, resisting the jarrin or vibrationor other effects incident to the -usual usage of the pointer or hand. Byproviding the area in arrow-head shape, as shown without the centralparting for a short distance from the tip, the most important portionfor night reading, namely, the end of the radio-luminous hand, is alsobetter protected to resist dislodging of the radio-luminous material dueto any variation -in temperature or in contracting of the material.Throughout the remaining length of lateral walls of the ridge, or thelateral edges may be in part or continuously turned up as 1n ig. 2*, andotherwise modified.

Terminating the ridge B part way between the tip and the hub a makes itpossible to efficiently and uniformly apply the radioluminous materialon the outer portion of the hand or pointer, for the desired length ofself-luminous area, and to omit it from the portion near-the hub inorder to save the expense of radio-active material.

In cross-section the hand may be readily,

made with the crimp B, as shown in Fig. 2,

with respect to convenience of manufactureof the hand proper, and afterdepositing the material for the self-luminosity the artisancan readilymanipulate a tool across the ridge B in order to clear the surface ofthe ridge,

leaving its contrasting color surface clear, and" thereby, assuringuniform thickness or depth of material for luminizing in thedark on suchlength of the hand as desired.

The construction shown in 2 involves the base J of the hand or pointerwith acentral slot into which a bent strip K is forced with oppositelyextending lips or flanges, which has at its-outer edge the narrowsurface H which may be bent or formed as rounded or flattened to providethe'necessary breadth or width of the line which is to form the daylightreading mark of the hand. In this formthe walls of the ridge member Kmay be so formed as to be reentrant to give .an added value in theholding of the laterally disposed radio-luminous material, and ifdesired'the edges may in part or whole be slightly turned up as shown.

In Fig. 2"the modification in the crosssection involves the base L onone side of which a small wire M is laid and secured thereby'forming aridge to provide the thedial day-reading line and to laterally providefor holding the radio-luminous material. f

It will thus be seen that the constructions described provide a ridge orridges intermediate the'side edges of a hand or pointer,-

which aid to secure, and which can serve to assure uniform'thicknessofthe radio-luminous material applied to the surface of the base.Furthermore, the ridge of rigid material forms the upper limit of thehand structure with the base at the bottom, so that both top and bottomare protected during the operation of the hands or pointers againstinterferin objects which might otherwise displied to hands of myconstruction, because the ridge in its various arrangements serves tocontrol the thickness and assure the efiiciency of the application ofmaterial either in base or other form with entire uniformity throughoutthe length of the head which it is desired to cover; thereafter theradio-active material of far lesser relative quantity may be readilydus'ted onto the surface or sprin kled on to the radio-responsive orsub-comund, as it is sometimes called; And in any nishing operations themanipulation of the tools will be subject to the control of the ridge inconjunction with the material borders of the hands, whereby uniformityof finish with economy in the operation is a result of great advantagefrom a manufacturing or studio work standpoint.

It will also be realized that a narrow line provided in the structure ofhands or dials as heretofore described, as well as many modificationsthereof, supplies a daytime visibility of a fine hair line which may beso narrow that it will in no way interfere with the luminosity indarkness of the adjacent radio-luminous areas. The light emis sion fromradio-luminous areas is "such that with a total area, and with a widthof luminous line in proportion to its length, sufficient for the desiredlegibility in the dark fora watch or clock or any other particular use,means that such light emission will have substantially the value of-theentire area of the hand or figure, and for night observation the narrowuncoated central rid e will not appear, i. e.,- it will practically "bebridged by the light emission from the ad jacent luminous areas.

Conversely, hands or figures constructed and-formed as heretoforedescribed may be offwhite or light tints matching the adjacent enam'elicolor .of a dial underlying the I hand, in which cases watches or clockswith their reading parts so constructed will have in daytimeasubstantially invisible breadth of hand, but a narrow clearly visibleline,

even a hair line, will constitute the central indicating or readingmarking for the hand and for the dial marking or figure with just asgreat accuracy for daylight use as any ordinary watch, clock orother-indicating device,-and' with no j apparent ncreased breadth in themarkings or hands during daytime reading. 4

The revolutionary development involved in the introduction ofreadable-in-the-dark watches, clocks, compasses and other indicatinginstruments and devices, is well, known to have involved at first theserious objection of making very broad hands and either large dots orgraduatio'ns or broad figures in order to provide a sufficient area sothat the permanent self-luminosity or radioluminous materials wouldserve the night reading object.- The clumsiness of such structuresimpeded for years the more general adoption of the day and nightreading-parts of timepieces and other instruments, and the necessityforproviding means so thatthe same night visible instruments would beequally readable by day, led to the provision of a border, or moreproperly two borders, one on either side of the selfluminous area. Suchborders on broadhands were an initial objection criticised asclumsiness, which the general usefulness of. 90

the self-luminous markings has but partially overcome. Initial attemptsin the'case of some instruments led to the use of a contrastingbackground, so that the white hand was bordered by a dark background butthis only made day reading relatively visible but still involved thebroad and inaccurate mark which is white for day reading and has thesame objections for many classesof timepieces as well asother devices.Added to the solution of the problem of producing reading parts of timepieces or other devices which can be accurately read in the daytime,

it will be seen that the structures heretofore described havemany addedadvantages, such as assuring uniformity in the amount or unformitythroughout the length of area of the luminous surfaces. Other advantageswill be appreciated in the practice of this invention, facilities formanufacture, as well aseconomies and speed of production with uniformityof product, add to the value and durability and other characteristics ofthe finished product.

While various modifications may be made in the structureandarrangements, as well 'as' the material and use of the articles, of

which specific embodiments have been heretoforedescribed, I do notconfine my invention to the specific forms shown inthe accompanyingdrawings and herein specified in detail,- but what I claim and.desire'to secure by Letters Patent is:

1. An article of the character described comprising a thin fiat base,two converging 130 depth of the coating of radio-luminous ma-' ridgesnear the outer end and a single central medial ridge formed on the basefrom near the tip toward the hub.

2. .A -hand or pointer for watches and like articles for dark and lightreading, including a base, a narrow medial non-luminous mark and arelatively broad radio luminous area on either side of said non-luminousmark substantially the' width of the base, and converging non-luminousborders of contrasting color near the outer end.

3. A hand or indicator for watches or like articles comprising a broadbase, radio luminous material covering the top side of the major portionof the base, a medial nonluminous line extending radially from the hubcentre of the hand and lateral juxtaposed ridges on opposite sides ofthe hand HERMANN 'F. CUNTZ.

Witnesses:

4 MARCUS J. BROOK,

J. H. OUNTZ.

